Current limiting properties of an expanding helical arc

Convoluted Arc With Flux Concentrator for Current Interruption

“…k, m and l reflect the coupling and mutual inductance losses of the flux concentrator in relation to the B-field producing coil [6,7]; and  is the transfer loss, which does not depend on the geometry of the flux concentrator, [6,7]. The values of k, l, m, L' and 3 L are shown on Table I. Based on an approximate theory [6,7] (i.e.…”

“…EVERAL evolving aspects of high voltage current interruption which are currently commanding attention include the interruption of direct currents (D.C.) rather than alternating currents (A.C.) and the drive towards avoiding the use of sulfur hexafluoride (SF6) gas as an arc quenching agent because of its potential for causing Global Warming [1]. Meanwhile, technology based upon the evolution of various forms of electromagnetic control of electric arcs has been investigated over several years with potential for current interruption applications [1][2][3]. Examples of particular forms of such devices include, as well, an electric arc convolute rotating around a polytetrafluoroethylene (PTFE) cylinder housing a magnetic field (B-field) producing coil, a similar arrangement with an outer PTFE cylinder with the arc rotating in the annular gap between the outer and inner PTFE cylinders etc.…”

A rotating arc gas pump for circuit breaking and other applications

“…Consequently, the axial mass flow rate of gas produced by the fan action can be formulated by integrating along the arc from the axis to the annular contact yielding [13] ( 3) where is the extent of axial displacement of arc root on the annular contact, and the radius of the annular contact. For the piston arc model, on the other hand, a simplified form of the momentum conservation equation may be written as the balance between the magnetic force on the arc and the axial momentum transferred to the surrounding gas (4) where is the radial magnetic field, is the circumferential component of arc current, is the circumferential length of the arc, is the arc diameter, and is the drag factor. This leads to the formulation of the axial mass flow rate due to the piston action as follows [13]: (5) To verify the two proposed models, the mass flow rate of the gas is measured and compared with both the fan and the piston models.…”